As a direct indication of an internal thermal process of the earth on the seafloor, terrestrial heat flow not only is a key parameter for understanding the heat diffusion rate of the earth, but also provides basic data for conducting geodynamic research, rebuilding the evolution of sedimentary basins, and evaluating the potential of oil, gas and hydrate resources. Therefore, it has national strategic significance to develop equipment for conducting seafloor heat flow measurements.
Seafloor heat flow can be measured by means of drilling temperature measurement and seafloor heat flow probes. Distribution areas for petroleum drilling and ocean drilling are limited, yet the seafloor heat flow probes are convenient for shipborne purposes with relatively flexible operation and lower cost and can carry out fine measurement in accordance with actual scientific issues and sea areas of interest, thereby being an important means for acquiring data on oceanic heat flows. In the 1950s, research scholars successfully carried out heat flow probing in sea areas of the North Atlantic Ocean by using a designed geothermal probe, which opened up an age of seafloor heat flow surveying. With the improvement of thermotechnical measurement theories and the advancement of technological methods thereof, as well as with the advancement and popularized application of computer technologies, large-scale integrated circuit technologies and storage technologies, the seafloor heat flow probe probing technology has also developed rapidly after almost half a century of development. The seafloor heat flow probes which are more mature and have been widely applied internationally today can be classified into two types, i.e., Ewing-type and Lister-type.
The above two types of probes in the prior art are available for acquiring seafloor geothermal parameters of sea areas where the bottom water temperature is stable over the long-term or smaller in fluctuations. But in some sea areas where the bottom water temperature tends to undergo larger periodical fluctuations, the temperature of surface sediments on the seafloor is also periodically influenced consequently so that geothermal gradients measured at the same site at different times change significantly, and the heat state of this site cannot be reflected truthfully, therefore, it is very difficult to acquire reliable data on seafloor heat flow in sea areas where the bottom water temperature has a larger fluctuation by using conventional seafloor heat flow probes (Ewing-type and Lister-type probes). Therefore, it is necessary to design a long-term monitoring base station with a reasonable structure for seafloor heat flow, to acquire more accurate and more reliable seafloor heat flow data in the sea areas where the bottom water temperature has a larger fluctuation, so as to meet the national strategic needs on carrying out basic research and resource surveys.